Egg Lipid Research Articles

The Effect of Lipids on the Structure and Function of Egg Proteins in Response to Pasteurization

In recent years, the consumption of liquid eggs has failed to meet the expectations of the public due to growing concerns regarding food safety and health. It is well known that there are interactions between the components in liquid eggs, and the interaction effect on the structure and functional properties of the proteins and antigenicity remains unclear. To investigate egg component interactions, we focused on four major egg lipids, namely phosphatidylcholine, palmitic acid, oleic acid, and linoleic acid, as well as four major egg proteins, including ovalbumin, ovotransferrin, ovomucoid, and lysozyme. The protein structural changes were analyzed using polypropylene gel electrophoresis, circular dichroism, ultraviolet absorption spectra, and exogenous fluorescence spectra, and the functional properties were assessed through solubility measurements and particle size analysis, while protein antigenicity was evaluated using an enzyme-linked immunosorbent assay. All the results revealed that oleic acid had the most significant effect on proteins’ secondary and tertiary structures, particularly affecting ovalbumin and ovotransferrin. Linoleic acid substantially increased the solubility of ovalbumin and ovomucoid, while palmitic acid significantly influenced the particle size of ovalbumin and lysozyme. Thus, we found that different lipids exhibit distinct effects on egg protein properties during pasteurization conditions, with oleic acid showing the most substantial impact on protein structure and antigenicity.

Different effects of low- and high-density lipoproteins in egg yolk on lipid metabolism of mouse: Role of phospholipids-to-cholesterol intake ratio.

Recent evidence increasingly indicates that moderate egg consumption (up to one egg per day) poses no significant risk of cardiovascular diseases in healthy individuals, leading researchers to speculate whether other lipids in eggs affect lipid metabolism. In this research, C57BL/6J mice were given chow diets containing egg yolk low-density lipoprotein (LDL) and high-density lipoprotein (HDL), two natural components with different proportions of phospholipids and cholesterol, to explore the effects of the phospholipids-to-cholesterol intake ratio on lipid metabolism. Increases in liver weight and liver index were observed following LDL intake, while body weight and epididymal fat decreased after HDL intake in a dose-dependent manner. The food efficiency of chow diets decreased with increasing phospholipids content. Lipid biomarkers indicated that LDL intake significantly increased plasma LDL cholesterol and liver cholesterol levels. At equivalent cholesterol doses, the cholesterol-raising effects of HDL were weaker than those of LDL. Higher protein expression of cytochrome P450 family 7 subfamily A member 1 in the HDL groups suggested increased bile acid excretion at higher phospholipids-to-cholesterol intake ratios. Fecal metabolite analysis revealed significant changes in lipid composition, primarily involving glycerophospholipids, sphingolipids, and sterol lipids, consistent with the lipid profiles of LDL and HDL. The upregulation of cholic acid and deoxycholic acid in feces further confirmed increased bile acid excretion. This study highlights the differences in lipid metabolism in mice under varying phospholipids-to-cholesterol intake ratios, which may be associated with changes in dietary energy supply and bile excretion following phospholipids involvement.

Lipidomics combined with random forest machine learning algorithms to reveal freshness markers for duck eggs during storage in different rearing systems

The differences in lipids in duck eggs between the 2 rearing systems during storage have not been fully studied. Herein, we propose untargeted lipidomics combined with a random forest (RF) algorithm to identify potential marker lipids based on ultra-performance liquid chromatography‒mass spectrometry (UPLPC-MS/MS). A total of 106 and 16 differential lipids (DL) were screened in egg yolk and white, respectively. In yolk, metabolic pathway analysis of DLs revealed that glycerophospholipid metabolism and sphingolipid metabolism were the key metabolic pathways in the traditional free-range system (TFS) during storage, glycosylphosphatidylinositol-anchored biosynthesis and glyceride metabolism were the key pathways in the floor-rearing system (FRS). In egg white, the key pathway in both systems is the biosynthesis of unsaturated fatty acids. Combined with RF algorithm, 12 marker lipids were screened during storage. Therefore, this study elucidates the changes in lipids in duck eggs during storage in 2 rearing systems and provides new ideas for screening marker lipids during storage. This approach is highly important for evaluating the quality of egg and egg products and provides guidance for duck egg production.

Evaluation and Discrimination of Lipid Components and Iron and Zinc Levels in Chicken and Quail Eggs Available on the Polish Market.

All over the world, birds' eggs are an important and valuable component of the human diet. This study aimed to compare the content of lipid components and their nutritional value as well as iron and zinc levels in chicken and quail eggs commonly available on the market. In egg lipids, unsaturated fatty acids were dominant, especially oleic acid, the content of which was about 40% of the total fatty acids (TFAs). Linoleic acid was the major polyunsaturated fatty acid. Compared to other products of animal origin, eggs were characterized by favorable values of lipid quality indices, especially the index of atherogenicity, thrombogenicity, and the hypocholesterolemic-to-hypercholesterolemic ratio. In the present study, no differences were found in the content of tested nutrients between eggs from different production methods (organic, free-range, barn, cages). Based on linear discriminant analysis, inter-breed differences were noticed. Cluster analysis showed that eggs enriched in n3 PUFAs (according to the producers' declarations) differed from other groups of chicken eggs. However, in eggs from one producer only, the amount of EPA and DHA exceeds 80 mg per 100 g, entitling the use of the nutrition claim on the package. Quail eggs differed from chicken eggs in FA profile and cholesterol and iron levels.

Metal accumulation in female green sea turtles (Chelonia mydas) from Eastern Atlantic affects their egg quality with potential implications for embryonic development

Sea turtles, with their global distribution and complex life cycle, often accumulate pollutants such as metals and metalloids due to their extended lifespan and feeding habits. However, there are limited studies exploring the impact of metal pollution on the reproductive health of female sea turtles, specifically focusing on the quality of their eggs, which has significant implications for the future generations of these charismatic animals. São Tomé Island, a crucial nesting and feeding habitat for green sea turtles, underscores the urgent need for comprehensive research in this ecologically significant area. This study aimed to investigate whether metals and metalloids in the blood of nesting female green sea turtles induce genotoxic effects in their erythrocytes and affect their egg morphometric characteristics and the composition of related compartments. Additionally, this study aimed to evaluate whether the quality of energetic reserves for embryo development (fatty acids in yolk's polar and neutral lipids) is influenced by the contamination status of their predecessors. Results revealed correlations between Cu and Hg levels and increased “lobed” erythrocytes, while As and Cu negatively influenced shell thickness. In terms of energy reserves, both polar and neutral lipid fractions contained primarily saturated and monounsaturated fatty acids, with prevalent 18:1n-9, 18:0, 16:0, 14:0, and 12:0 fatty acids in yolk samples. The yolk polar fraction was more susceptible to contaminant levels in female sea turtles, showing consistent negative correlations between pollution load index and essential n3 fatty acids, including linolenic, eicosatrienoic, eicosapentaenoic, and docosapentaenoic acids, crucial for embryonic development. These metals accumulation, coupled with the reduced availability of these key fatty acids, may disrupt the eicosanoid and other important pathways, affecting reproductive development. This study reveals a negative correlation between metal contamination in female sea turtles' blood and egg lipid reserves, raising concerns about embryonic development and the species' future generations.

Differentiation of lipid profiles of hen eggs from different regions based on lipidomics combined with chemometrics

Hen egg yolk lipids from different regions were determined by ultra-high-performance liquid chromatography with high-resolution mass spectrometry. A total of 15 lipid classes and 346 lipid molecular species were tentatively identified. Principal component analysis showed that the egg lipid profiles varied a certain extent across different production regions. Hierarchical cluster analysis indicated that the egg lipid compositions from Jiangsu and Chungking were relatively similar, but significantly different to those from Inner Mongolia, Jiangxi, and Hainan. Differences in the content of some lipid molecules are obvious, for instance, the concentration of lysophosphatidylcholine (18:1/0:0) in Jiangsu egg and Chungking egg, and phosphatidylinositol (18:0/20:4) in Hainan egg, Changde egg and Jiangxi egg varied significantly from other origins. This study provides a foundation for comprehending the impact of diverse geographical environments on egg lipid profiles.

Thiamine Deficiency M74 Developed in Salmon (Salmo salar) Stocks in Two Baltic Sea Areas after the Hatching of Large Year-Classes of Two Clupeid Species—Detected by Fatty Acid Signature Analysis

Lipid-related thiamine (vitamin B1) deficiency of Baltic salmon (Salmo salar), the M74 syndrome, is generally caused by feeding on abundant young sprat (Sprattus sprattus) in the Baltic Proper, the main foraging area of these salmon. In 2014, a strong year-class of sprat was hatched in the Baltic Proper, and a strong herring (Clupea harengus) year-class was hatched in the Gulf of Bothnia, where herring is the dominant salmon prey. The fatty acid (FA) signatures of prey fish in muscle or eggs of second sea-year spawners suggested that 27% of wild River Simojoki and 68% of reared River Dal salmon remained in the Gulf of Bothnia in 2014 instead of continuing to the Baltic Proper. In 2016, 23% of the M74 females of the River Simojoki and 58% of the River Dal originated from the Gulf of Bothnia, and 13% and 16%, respectively, originated from the Baltic Proper. Some salmon from the River Neris in the southern Baltic Proper had also been feeding in the Gulf of Bothnia. In general, low free thiamine (THIAM) concentration in eggs was associated with high lipid content and high docosahexaenoic acid (DHA, 22:6n−3) and n−3 polyunsaturated FA (n−3 PUFA) concentrations in muscle but not in eggs. A higher THIAM concentration and lower proportions of DHA and n−3 PUFAs in Arctic Ocean salmon eggs, despite higher egg lipid content, indicated that their diet contained fewer fatty fish than the Baltic salmon diet. Hence, M74 originated by foraging heavily on young fatty sprat in the Baltic Proper or herring in the Gulf of Bothnia.

The impact of post-ovulatory ageing on the development of diploid and triploid Atlantic salmon (Salmo salar L.)

This study is the first to investigate the effects of post-ovulatory ageing (POA) on both diploid and triploid Atlantic salmon (Salmo salar L.). Following ovulation, female broodstock were partially stripped periodically (at 0, 5, 10, 15 and 20 days post-ovulation, DPO), creating five groups of ova with differing durations held in the body cavity. Survival and bone architecture were negatively impacted by increasing POA, irrespective of ploidy, and an increase in individual growth variation was observed, particularly in triploids. Several ovarian fluid and egg quality parameters were screened to determine potential prospective biomarkers that may predict the future success of an egg batch. Ovarian fluid osmolality and egg lipid composition, vitamin E concentration and TBARS emerged as good candidates. Furthermore, significant changes in abundance of 19 proteins involved in cell organisation, metabolism and reproduction were observed at different stages of POA. Also, a suite of genes involved in energy metabolism, apoptosis and cell cycle regulation showed significantly reduced expression in eggs at 20 DPO compared to 0 DPO. The data show that increasing POA negatively impacts egg survival and future growth and increases deformity prevalence. Several potential biomarkers show promise and should be investigated further. Although egg quality appears to remain stable up to 10 DPO, the data suggests that fertilising eggs within 5 DPO would reduce the variation in growth, thus improving future performance potential and further benefitting stock management of both diploid and triploid Atlantic salmon.

Supplementation of hen diets with dried or freshly harvested Talinum triangulare: the effect on egg production and egg lipid profile

This study investigated the comparative effects of administration of dried and fresh Talinum triangulare (Tt) plant supplements on the egg production and egg quality of laying hens. Two hundred and ten pullets, purchased at the age of 18 weeks, were randomly assigned to seven study groups: A1 , A2 , A3 ; B1 , B2 , B3 ; and C. Aqueous extracts derived from a dried sample of Tt were administered at 62.5, 250, and 1000 mg/L doses for treatment of Group A (A1, A2, and A3 ); or from freshly harvested samples of Tt at 62.5, 250, and 1000 mg/L dose for treatment of Group B (B1 , B2 , and B3 ). Hens in Group C (CC) served as an un-supplemented experimental control group. Laying rate and egg lipid profile were determined at two-month intervals following standard procedures. Supplementation with Tt significantly enhanced egg production, with extended higher laying rates in groups A and B. A significant (P<0.05) reduction in low-density lipoprotein (LDL) concentration and an increase in the high density lipoprotein (HDL) concentration of eggs were observed in the supplemented groups (A and B). Dietary supplementation with dried samples of Tt at doses of 250 and 1000 mg/L increased the number of eggs laid, and resulted in the production of eggs with lower LDL and higher HDL cholesterol. Further research is needed to elucidate the exact mechanisms behind the hypolipidemic principle and egg production enhancement.

Ashwagandha (Withania somnifera) Kök Tozunun Yumurtacı Tavuklarda Performans, Yumurta Kalitesi ve Yumurta Sarısı Lipid Peroksidasyonu Üzerine Etkileri

This study was conducted to determine the effects of different levels (0, 200, 400, 600 mg/kg) of ashwagandha (Withania somnifera) root powder (ARP) on performance, egg quality and egg lipid peroxidation in laying hens (Lohmann LSL, 36 weeks old) diets. For this purpose, a total of 4 groups were formed, one of which was control (ARP-0) and the other three were experimental groups (ARP-1, ARP-2, ARP-3). A total of 96 hens were distributed to 4-storey cages with 8 replicates in each group and 3 hens in each replicate. The experiment lasted for a total of 2 months. During this period, feed and water were given as ad-libitum and 16 hours of light and 8 hours of dark photoperiod was applied daily. The ARP-0 group was fed with basal diet and the experimental groups were fed with diets prepared by adding 200, 400 and 600 mg/kg levels of ARP to the basal diet, respectively. Except for egg weight, albumen index, Haugh unit, shell weight, yolk L* and b* and TBARs (day 0), other parameters were not affected by ARP in the diet. The highest egg weight (p

The effect of temperature and dietary energy content on female maturation and egg nutritional content in Atlantic salmon.

The environment experienced by a female influences reproductive traits in many species of fish. Environmental factors such as temperature and diet are not only important mediators of female maturation and reproduction but also of egg traits and offspring fitness through maternal provisioning. In this study, we use 3-year-old tank-reared Atlantic salmon from two Finnish populations to investigate the effect of temperature and diet on maturation and egg traits. We show that a temperature difference of 2°C is sufficient to delay maturation in female Atlantic salmon whereas a 22% reduction in dietary energy content had no effect on maturation. Diet did not influence the body size, condition or fecundity of the mature females or the size or protein content of the eggs. However, a higher energy diet increased egg lipid content. Neither female body size nor condition were associated with egg size or fat/protein composition. Our results indicate that female salmon that have a poorer diet in terms of energy content may have a reproductive disadvantage due to the lower energy provisioning of eggs. This disadvantage has the potential to translate into fitness consequences for their offspring.

Egg yolk lipids induce sensitization to egg white proteins in a mouse model without adjuvant and exacerbate Th2 responses to egg white in cells from allergic patients

This study evaluates the influence of egg lipid fractions in the induction of allergic sensitization to egg white (EW) proteins, using a mouse model of orally adjuvant-free induced allergy. Egg triglycerides (TG) and phospholipids (PL), and to a higher extent the whole egg lipid fraction (EL), induced allergy to EW proteins characterized by increased EW-specific IgG1. EL also increased EW-specific IgE. The administration to mice of a mixture of EW and EL increased the intestinal expression of Il33, Il25, and Tslp, the secretion of IL-33 and IL-6, the expansion of group 2 innate lymphoid cells, the regulation of Gata3, Il4 and Il13, dendritic cell (DC) activation and expression of DC molecules that drive Th2 differentiation. TG promoted the absorption of proteins through the intestinal epithelium, enhancing local Th2 responses, while PL favoured the delivery of antigens to the Peyer’s Patches. This differential modulation of the site of absorption of egg proteins determined the different behaviour of TG and PL. Egg yolk lipids also induced activation of Th2-inducing innate responses on intestinal human cells in vitro and enhanced adaptive Th2 functions through the activation of DCs in egg-allergic subjects.

Rheology and dispensing of real and vegan mayo: the chickpea or egg problem.

The rheology, stability, texture, and taste of mayonnaise, a dense oil-in-water (O/W) emulsion, are determined by interfacially active egg lipids and proteins. Often mayonnaise is presented as a challenging example of an egg-based food material that is hard to emulate using plant-based or vegan ingredients. In this contribution, we characterize the flow behavior of animal-based and plant-based mayo emulsions, seeking to decipher the signatures that make the real mayonnaise into such an appetizing complex fluid. We find that commercially available vegan mayos can emulate the apparent yield stress and shear thinning of yolk-based mayonnaise by the combined influence of plant-based proteins (like those extracted from chickpeas) and polysaccharide thickeners. However, we show that the dispensing and dipping behavior of egg-based and vegan mayos display striking differences in neck shape, sharpness, and length. The ratio of apparent extensional to shear yield stress value is found to be larger than the theoretically predicted square root of three for all mayo emulsions. The analysis of neck radius evolution of these extension thinning yield stress fluids reveals that even when the power law exponent governing the intermediate pinching dynamics is similar to the exponent obtained from the shear flow curve, the terminal pinching dynamics show strong local effects, possibly influenced by interstitial fluid properties, finite drop size and deformations, and capillarity.

Effects of Dietary Rapeseed (Brassica napus), Hemp (Cannabis sativa) and Camelina (Camelina sativa) Seed Cakes Supplementation on Yolk and Albumen Colour and Nutritional Value of Yolk Lipids in Estonian Quail Eggs.

The aim of this study was to investigate the effects of supplementing commercial diets with rapeseed, hempseed and camelina seed cakes on the yolk and albumen colour and nutritional value of yolk lipids in Estonian quail eggs. A total of 585 eggs were used to evaluate egg weight, yolk and albumen pH and colour, proximate yolk composition, cholesterol content and fatty acid composition in the yolk lipids of three Estonian quail groups each fed a diet supplemented with 10% rapeseed, hemp or camelina seed cakes. The higher (p < 0.01 and p < 0.05, respectively) lightness (L*) of the yolk was detected in the group of quail fed the diet supplemented with rapeseed and camelina cakes compared to the hempseed addition. Meanwhile, the albumen lightness in the rapeseed group was higher (p < 0.01) in comparison to the camelina group. A lower (p < 0.001) yolk negative a* value was estimated in the hemp group than in the groups fed rapeseed and camelina seed cake supplements, while the rapeseed group demonstrated lower (p < 0.001) albumen yellowness (b*) and colour saturation (C) in comparison to the other groups. The highest and lowest proportions of total saturated (SFAs)and monounsaturated (MUFAs) fatty acids, respectively, were found in the yolk lipids of quails fed a mixture supplemented by hemp cake. A higher (p < 0.05) proportion of polyunsaturated fatty acids (PUFAs) was only found in the hemp group compared to the camelina group. The highest and lowest (p < 0.001) n-6/n-3 PUFA ratios were found in the yolk lipids of quail receiving mixtures supplemented with rapeseed and camelina cakes, respectively. The yolk of the quail from the rapeseed group showed more favourable lower and higher (p < 0.01 and p < 0.05, respectively) atherogenic index (AI) and hypocholesterolemic/hypercholesterolemic (h/H) ratio compared to the hemp and camelina groups. The lower yolk cholesterol content was found in the eggs of the quail fed the diet supplemented with rapeseed cake compared to the eggs of the quail which were fed the diets containing more n-3 PUFAs from the addition of hemp and camelina cakes (p < 0.05 and p < 0.01, respectively).

Long term environmental variability modulates the epigenetics of maternal traits of kelp crabs in the coast of Chile

The methylation of DNA is an environmentally inducible epigenetic mechanism reflecting the short‐term ecological and environmental background of populations. Marine invertebrate populations, which spread along a latitudinal cline, are particularly suitable for profiling DNA methylation, due to the heterogenous environmental conditions experienced. We used the MSAP (Methylation Sensitive Amplified Polymorphism) technique to investigate the natural variation in DNA methylation of different female’s tissues (muscle, gonads, and gills) and early-stage eggs from five populations of the kelp crab Taliepus dentatus, distributed along a latitudinal cline in the coast of Chile. We assessed whether, (1) the distribution of DNA methylation profiles can be associated with the temporal variability of long term (18 years) climatologies (sea surface temperature, turbidity and productivity) and (2) the epigenetic diversity of eggs is related to the population-level phenotypic variability of several maternal investment traits (egg volume, egg weight, egg lipids and fecundity). The DNA methylation of eggs correlated positively and negatively with the long term variability in productivity and sea surface temperature, respectively. Furthermore, the diversity of DNA methylation of eggs correlated positively with the population-level phenotypic variability of several maternal investment traits, suggesting a key role of epigenetic mechanisms in generating phenotypic variability at population level for this species. We provide evidence of a strong link between the temporal variability of long term climatologies with the epigenetic profiles of key early ontogenetic traits associated with the maternal investment of kelp crabs. These modulating mechanisms can hence contribute early to phenotypic variability at population levels in response to local and past environmental fluctuation.

Recent Advances in Single-Cell Metabolomics Based on Mass Spectrometry

Recent Advances in Single-Cell Metabolomics Based on Mass Spectrometry

The association of Curcuma and Scutellaria plant extracts improves laying hen thermal tolerance and egg oxidative stability and quality under heat stress conditions

Chronic exposure to high ambient temperatures is detrimental to laying hen performance and egg quality. Plant secondary metabolites may alleviate effects, partly due to their antioxidant activities. Herein, we investigated the effects of dietary supplementation with a phytonutrient solution (PHYTO) consisting of a plant extract combination of Scutellaria baicalensis and Curcuma longa on young layers (25–32 wk of age) raised under naturally elevated temperature conditions. Four hundred, 24-wk-old Lohmann hens were allocated in 50 cages and, after a week of adaptation, were offered a diet either containing 2 g/kg of PHYTO or not, for 8 wk. Hen BW was measured at the beginning and end of the trial, and egg production and feed intake were recorded weekly. At week 32, four eggs per cage were collected to determine egg quality characteristics as well as the rate of lipid and albumen oxidation in fresh eggs. At the end of the trial, two hens per cage were blood sampled for assessment of biochemical markers, one of which was euthanized for histopathological evaluation of the liver and intestine and assessment of intestinal histomorphometry. The herbal mixture supplementation significantly increased egg production rate at weeks 28 and 29 and for the overall production period, and feed efficiency at weeks 26–29. In addition, the degree of liver necrosis and microvascular thrombosis was lower (P < 0.05) whereas intestinal villosity was greater in duodenal and jejunal segments (P < 0.05) in the PHYTO compared to the control group. Supplementation also reduced (P < 0.05) blood concentrations of corticosterone, alanine aminotransferase activity, and TBARS, and a reduction in catalase activity was observed. Egg quality characteristics were not affected, except for eggshell thickness, egg diameter, and eggshell breaking strength that were superior in the PHYTO group (P < 0.05). PHYTO supplementation significantly improved egg lipid oxidation status of fresh eggs. In conclusion, supplementation with PHYTO improved laying hen productivity and egg quality, which was associated with an improvement in laying hen thermotolerance.

Responses of egg quality sustainability, sensory attributes and lipid profile of eggs and blood to different dietary oil supplementations and storage conditions

The aim of this study is to investigate the responses of egg quality, sensory attributes and lipid profile of eggs and blood serum to different combinations of dietary oil supplementations and storage conditions. Thus, laying hens aged 25 weeks were assigned to six experimental groups and fed different diets for 14 weeks. The group fed an unsupplemented diet served as control, while the other five treatment groups consumed the same basal diet supplemented with 5% corn oil, 5% linseed oil, 2% corn oil + 3% linseed oil, 3% corn oil + 2% fish oil and 3% linseed oil + 2% fish oil, respectively. After 10 weeks, 36 eggs were collected from each experimental group and divided into three sets of 12 eggs to compare the quality of fresh eggs with those obtained after 21 days of storage at 23 °C and 5 °C. In addition, 20 untrained panellists evaluated the sensory characteristics of fresh eggs. Except for shell thickness, shell percentage and shell weight per unit of surface area (SWUSA), the supplementation of oil did not affect the egg quality parameters. The eggs laid by hens fed 3% corn oil and 2% fish oil had the highest quality shells, while the eggs from the control group had the best albumen colour, flavour and general acceptance. However, only shell percentage and shape index were unaffected by storage conditions, while all other parameters were significantly lower in eggs stored at 23 °C for 21 days. Although dietary oil supplementation did not significantly improve egg quality, feeding 3% corn oil and 2% fish oil improved eggshell quality, which declined with increasing storage temperature/period. HIGHLIGHTS Dietary oils are essential components of poultry diets and animal nutrition. Sensory attributes are essential for human acceptance of animal products. Lipid profile may reflect lipid utilisation and efficiency. Different dietary oil combinations affect the eggshell quality and sensory attributes of eggs. Linseed oil enhanced the nutritional value of egg lipids and serum lipid profiles.

Egg Lipid Profile, Growth Traits, Blood Biomarkers, and Physical Egg Characteristics of Heavy Ecotype Laying Hens Fed Oregano (Origanum vulgare) Meals

Investigation on the effect of dietary oregano on growth traits, egg physical characteristics, blood biomarkers, and egg lipid profile of heavy ecotype laying hens was conducted. Two hundred and forty eighteen weeks old, heavy ecotype hens were randomly assigned to two (T1; control - zero oregano meals, and T2; 3g oregano meals kg-1) dietary treatment of twelve replicates with ten hens per replicate. Birds fed oregano meals improved body weight and weight gain (P&lt;0.05) compared with those fed the control diet. The heavy ecotype-laying hens fed zero oregano consume more (P&lt;0.05) diets with a poor FCR. Egg production and egg weight were higher for birds fed oregano meals. Birds fed dietary oregano supplementation had a better (P&lt;0.05) shell thickness than those fed the control diet. Red blood cell (RBC) and hemoglobin (Hb) values were higher for birds fed dietary oregano, as shown in Table 6. White blood cell (WBC), lymphocytes, monocytes, and eosinophil counts were increased (P&lt;0.05) for birds fed the control diet in contrast to those that received oregano inclusion. Cholesterol, high-density lipoprotein (HDL), as well as low-density lipoprotein (LDL) were affected by the dietary oregano. Cholesterol and LDL levels were higher (P&lt;0.05) for birds fed the control diet. At the same time, those that received oregano inclusion had a higher HDL value as well as a reduced (P&lt;0.05) cholesterol and LDL values. It was concluded that oregano improved egg mass, egg quality, and quantity. It also enhanced the immunity of the hens.

The biological significance of lipogenesis in Nasonia vitripennis.

Parasitic wasps have long been thought to be unable to synthesize fatty acids de novo, but recent 13C-labelling studies have challenged this view. It remained unclear, however, whether the reported biosynthesis rates are of biological relevance. Here, we show in Nasonia vitripennis that ageing females with partly depleted lipid reserves produce biologically relevant amounts of fatty acids de novo. Females with varying oviposition history (0-48 h) prior to feeding 20% 13C-labelled glucose solution showed 13C-incorporation rates of (mean ± SEM) 30 ± 2%, 50 ± 2%, 49 ± 3% and 21 ± 2% in palmitic, stearic, oleic and linoleic acid, respectively. The absolute amounts of fatty acids synthesized de novo across treatments corresponded to 28 ± 3 egg lipid equivalents. Females incorporated de novo synthesized fatty acids into their eggs, and glucose-fed females laid more eggs than water-fed control females. The number of eggs laid prior to glucose feeding did not correlate with the degree of lipogenesis, but the amounts of de novo synthesized fatty acids correlated with constitutive (not synthesized de novo) fatty acids. Hence, glucose feeding has a twofold effect on the fatty acid status of N. vitripennis females by decelerating the catabolism of existing fat reserves and partially replenishing ebbing fat reserves by lipogenesis.